I have not experienced what you describe. I am 65 - I have worn glasses since I was 12. One quick and easy thing to check is whether or not your scope is focused - most scopes have a lock ring at the rear end to "lock" the eye piece - the eye piece will screw in or out and then gets "locked". As per instructions that would have came with that scope - aim up at sky / clouds / a blank wall - do not want to focus at a "thing" - you want to be looking at infinity. Turn eye piece in or out - take another look - do not stare - after a few seconds, your eye will try to change to accommodate the vision - what you are after is to get the cross hairs to appear as crisp and sharp as you can get them - at the first glance - when looking at infinity. That will get that scope set for your vision at all ranges. May or may not work for the next guy to use it, but that is why it is adjustable.
With practice, you can very much train your brain to accept two different images at the same time - the business of shooting with both eyes open. With scopes, is easier, I found, to start with lower power like 2.5. Then move on to 4. I shot my last elk, it was on the run at about 125 yards, in bush, with a 6 power scope. You will get to the point of looking at what you want to hit - with both eyes open - rifle comes up and the cross hair is super-imposed on the scene - fire when it is all as you want it. It is possible that I close my left eye at the moment of firing - not real sure of that...
I was thinking about your issue of seeing the top of your eyeglasses frame. I suspect that is occurring because you are hunched way down on the rifle stock - so, perhaps try to use higher sandbags - get the rifle up higher - that way your head would be more erect, and should be more looking through the centre part of your lenses, where the best correction will be? That is all just a guess - I was trying to figure out how the glasses frame could be in the way, and the head tipped forward is the only way that I can see that happening? Sort of like when shooting a hard recoiling rifle like a 338 Win Mag or a 375 H&H - want to be sitting more up-right, with your head up - otherwise will pound you pretty good...
